1. Field of the Invention
The present invention relates to manually operated shoveling and plowing devices, and more particularly to a manually operated shoveling device capable of scraping and gathering, lifting, and dumping large quantities of a granular or other material such as snow quickly and with a minimal amount of physical exertion and strain on the operator.
2. Preliminary Discussion
Well known is the fact that shoveling snow with a conventional shovel is very labor intensive and places considerable stress on the shoveler's body. A Journal of the American Medical Association study found that people who rarely exercise are up to 30 times more likely to have a heart attack when suddenly undertaking a strenuous activity such as snow shoveling. The physical labor of shoveling quickly drives up one's blood pressure and heart rate, particularly in those people who are out of shape and not used to regular physical exertion. Cold weather only adds to the stress, because the cold tends to constrict blood vessels, not only at the surface of the body, but generally, while at the same time extra blood is needed flowing to the heart to compensate for the workout. The main reason for the initiation of such injury during shoveling is that the amount of stress exerted is usually underestimated by the shoveler. Researchers in Michigan recently monitored the vital statistics of 10 healthy men in their 20's and 30's, including heart rate, as they ran on a treadmill to the point of exhaustion. Shortly thereafter, the same group was monitored as they shoveled heavy, wet snow for about ten minutes. The results showed that the men's heart rates during or after shoveling were at least as high or higher than their heart rates on the treadmill.
In addition to risk of heart attacks, the stress of shoveling can lead to other serious physical injuries, the most serious of which are usually back injuries. In fact, although one might think that older individuals are more at risk of suffering a back injury while shoveling, shovelers between the ages of 20 and 50 are generally more likely to suffer a back injury than older individuals, because older individuals are more likely to be aware they are out of condition, and therefore more likely to “take it easy” so to speak. The risk of suffering a back injury is also more likely in the morning because the tissue around the shoveler's spine is not warmed up or loose. Many slipped discs also occur in the morning when there is increased fluid pressure in the cerebrospinal fluid which increased pressure is exerted upon and internally of the disc. Resulting “over inflation” of the disc increases the likelihood of the top and bottom of the disc moving laterally relative to each other.
Use of proper lifting technique and shoveling at a slower, steady pace can greatly reduce the risk of injury while shoveling. For example, in lifting a loaded shovel, the shoveler should bend his or her knees while lifting with the legs and not with the back. Excessive twisting, bending or throwing snow over the shoulder should be avoided to prevent spinal injury, as the spine can tolerate almost any other movement more easily than twisting. Stepping in the direction the snow is being thrown will also prevent some twisting. In addition, smaller shovel loads should be lifted rather than heavy or full shovel loads. Frequent breaks should be taken, and the lower back should be extended either by walking around or doing extension exercises by placing one's hands on the back of his or her hips and bending forward slightly for several seconds, and then bending backward also for several seconds.
Despite such precautions, which are not taken by most or even many shovelers, muscle fatigue, low back strain, vertebral disc damage, and even spinal fractures occur during the winter season, caused either by excessive stress to spinal structures and others by slip and fall accidents. Thus, since most of such shoveling injuries occur as a result of lifting and throwing or dumping loads of snow, an even better solution to preventing injuries to one's back or other muscles is to push the snow to the grassy area beside a sidewalk or driveway instead of lifting and throwing it. Some back injuries occur due to the fact that the shaft of the shovel is too short, which causes the back to bend more to lift the load, or by using a shovel with a shaft that is too long, the resulting excessive leverage effectively making the weight at the end relatively heavier. In addition, several shovels today have curved shafts or handles which enable the user to keep his or her back straight or straighter while lifting and reduce the amount of bending required during use. Such curved shaft shovels, however, in general place even more stress on the body if the snow has to be lifted up to or over a pile of previously collected snow or other barrier. Other snow handlers choose to do away with manual shoveling altogether, and instead use a snow blower. However, while snow blowers do in fact eliminate lifting of snow, they are quite expensive to purchase and maintain, and can be dangerous if not used or cleaned correctly. In fact, hand injuries caused by cleaning out a snow blower by hand are quite common, despite repeated warnings. Snow blowers, furthermore, are inefficient with heavy wet snow, which is also the most difficult to move by means of a shovel.
As discussed in more detail in reviewing the prior art references below, in an attempt to reduce the exertion and amount of lifting required, the principle of leverage has been adopted for use in various shovel arrangements. In most cases, the shovel shaft or handle acts as an extended lever which is pivoted against a fulcrum attachment to lift a load, in this case a shovel blade loaded with snow. Essentially, by applying a downward lift force on the lever, the amount of work required to lift the loaded shovel is reduced. The human body or more specifically the arm is itself essentially a third class lever, i.e. the fulcrum point is at the end of the lever and the exertion of force is between the fulcrum point and the point at which force is to be exerted. However, third class levers offer no advantage to gravity in terms of power, since they require more force to move against the force of gravity than the weight to be moved. For example, to lift twenty pounds with one's hand, the arm muscles actually put about two hundred pounds of force on the forearm, so that the force that goes into the body is approximately ten times the force being lifted. Therefore, while third class levers such as the human body or more particularly the arms are good for mobility and speed, they are very inefficient in terms of lifting against the force of gravity and/or in terms of energy. In addition, the load is supported by an articulated but only partially flexible column represented by the spinal column maintained in alignment by multiple individual muscles and tendons which must operate in complete coordination to prevent misarticulation, which is a primary reason why back injuries often occur while lifting heavy items. The entire weight, whatever it is furthermore in shoveling, is exerted upon the spinal column with a significant twisting moment made greater by the length of the shovel handle. Second class levers, an example of which is a wheelbarrow, where the weight of the load is exerted between the fulcrum point and the point of exertion of lifting force and thus attains a mechanical advantage, offer some additional mechanical advantage, but the load is still essentially placed so that to get any such mechanical advantage, one is still lifting up against the force of gravity. In a wheelbarrow, the load is situated essentially behind or right over the fulcrum, and one must lift up against gravity to move the load. In a first class lever, however, such as a shovel having a fulcrum type attachment, one pushes down in the same direction as the force of gravity on the handle, which is easier than lifting against gravity, causing the other loaded end to be lifted upwardly. The longer the lever on the down side of the fulcrum in comparison to the load side, the less effective force is required to lift the load. Approximately thirty-three pounds of down force on one side of the lever, which force is enhanced by the force of gravity, is translated into a hundred pounds of up force on the opposite side of the lever if the downward force application side is three times as long as the lift side.
The present inventor has conceived of a novel snow shoveling device wherein all of the lift required in lifting a load of snow comes from a unique first class lever arrangement in which the handle of the shovel serves as the fulcrum support. As a result, little or no physical exertion other than pushing the shoveling device across the area to be cleaned and pushing downwardly on the lever mechanism with one's body weight, preferably by the use of the large leg muscles rather than the relatively smaller arm muscles, is required. In addition, once the load is lifted, such load is easily released from the shoveling blade again with only minimal physical strain or exertion when compared to the large strain on the heart and muscles in shoveling using a regular hand shovel. Even more important in the present invention, however, is that instead of the weight of the snow or other congealed precipitation being supported during lifting by the articulated cervical column of the shoveler of the snow, the weight of the snow is supported by the much more durable and damage resistant handle of the shovel which rests upon the underlying surface from which the snow is being removed during lifting and the downward force is applied as indicated to the leveraged shovel blade not by the relatively weak muscles of the arms, but by the considerably more powerful muscles of the legs or one leg, further removing, stress from the spine, since the legs of the human torso are articulated into the hips below the spine. The only stress to the spine, therefore, is the relatively low stress of maintaining the shovel handle upright upon the surface from which snow is being removed, and even this stress comprises only a relatively low sidewise force effective to maintain the shovel handle essentially upright. Furthermore, even this low stress can be partially alleviated by providing multiple point, such as four point, bottom contact of the shovel handle with ground surface. The actual dumping of snow from the shovel blade once it is elevated can be effected in several different ways, as will be explained, such as overbalancing of the shovel blade and the use of push rod means to rotate the blade.
3. Description of Related Art
As indicated above, various arrangements are known in the prior art which are designed to lessen the amount of work and physical exertion involved in lifting a load using a shovel. Many of these arrangements involve a use of fulcrumed load lifting. However, none of such arrangements of which the present inventor is aware involve the use of a handle which supports a lifting fulcrum against the support of the ground.
One common device is the addition of an auxiliary handle to a shovel normally having a single gripping area on the upper end of the regular handle. For example, U.S. Pat. No. 584,827 issued to B. F. McIndoo on Jun. 22, 1897, entitled “Shovel,” is an early example of a shovel having an auxiliary handle pivotably connected to the lower end of the regular handle. To lift a load, the auxiliary handle is swung forwardly where it is held by a pawl and rack arrangement. When the load is ready to be pitched off the shovel blade, the pawl is disengaged from the rack and the auxiliary handle is allowed to naturally swing backwards toward the upper end of the regular handle. In U.S. Pat. No. 4,198,090 issued to D. Gutman on Apr. 15, 1980, also entitled “Shovel,” teaches a shovel having an adjustable lever situated partway along the handle portion of the shovel and a secondary handle member connected to the upper handle portion of the shovel. Gutman also utilizes a lever mechanism to aid in initially lifting a load on the scoop member; however, considerable lifting and strain is still required to support and dump the load.
As another example, in U.S. Pat. No. 4,881,332 issued to G. L. Evertsen on Nov. 21, 1989, entitled “Shovel Lifting Aid,” a shovel handle having a swivelable bar connected thereto and arranged so that when the user's foot is placed on the bar and the shovel blade is filled with a load, the load is lifted by pulling rearwardly on the handle until the load is essentially balanced on the lifting aid. Once lifted, the handle may be pivoted to the side to dump the load. A wheel arrangement as part of the lifting aid is also contemplated. In U.S. Pat. No. 5,440,828 issued to R. C. Simpson on Aug. 15, 1995, entitled “Manual Snow Removal Tool,” a shovel in which the handle is pivotable to either side within a range of angular positions with respect to the blade is shown, which allows the shovel to be used both conventionally to scoop and then lift and throw a load of snow, or to windrow the snow when the handle is set at an oblique angle with respect to the blade.
A large number of shovels having fulcrum or pivot attachments are also well known. U.S. Pat. No. 738,057 issued to E. B. O'Connor on Sep. 1, 1903, entitled “Shovel Attachment,” discloses a fulcrum type attachment for a shovel that acts as a rocker on which the shovel rests and rocks as the shovel is moved forward or rearward. Rocking of the shovel on the fulcrum eliminates the need to stoop to fill the shovel.
U.S. Pat. No. 2,734,291 issued to C. C. Lasker on Feb. 14, 1956, entitled “Manually Operated Snow Removal Tool,” discloses a scoop or shovel having a pair of curved combination rocker and skids connected to the back of the shovel blade. In use the shovel blade is pushed over the surface to be cleaned, and then is tilted upwardly by pushing down on the handle so that the shovel blade is pivoted off the ground and is supported on the rocker and skids. The tool is then pushed to a dumping area on the skids and pivoted forwardly onto the front edge of the blade so that the snow will simply slide off the blade. While Lasker eliminates lifting of the loaded shovel, it may be difficult to dump the snow if more than a few inches has fallen since the blade is always at more or less ground level.
U.S. Pat. No. 2,769,612 issued to C. Weisheit on Nov. 6, 1956, entitled “Shovel With Lifting Means,” discloses a shovel having attached both an auxiliary handle and a fulcrum or lever device. The fulcrum or lever is connected to the bottom side of the shovel handle via a plate member, while the pivotable handle is connected to the upper side of the shovel handle. A spring arrangement is also used to continually urge the shovel blade into contact with the ground. Pulling upwardly on auxiliary handle and pushing downwardly on the regular handle causes the shovel blade to pivot upwardly so it is balanced on the fulcrum or lever. Such system aids in the initial lifting process but still requires the user to support the entire weight of the load of snow prior to dumping.
U.S. Pat. No. 3,035,816 issued to M. A. Conant on May 22, 1962, entitled “Foot Lever for a Hand Shovel,” discloses another lever device which when downward pressure is placed on the foot pedal, the lever rocks so that the loaded shovel blade is forced upwardly. If enough downward force is placed on the foot lever, the snow or load will continue moving in an upward direction and may then be easily deflected to the side by turning the shovel handle or blade.
U.S. Pat. No. 3,343,807 issued to A. L. Moraski on Sep. 26, 1967, entitled “Shovel,” discloses an arrangement similar to that found in Lasker but with a pair of arcuate legs forming a fulcrum point for pivoting the shovel blade upwardly. In addition, a pair of roller wheels are provided to facilitate forward or rearward movement of the shovel.
U.S. Pat. No. 3,748,761 issued to C. H. Chetwynde on Jul. 31, 1973, entitled “Snow Handling Device,” discloses a shoveling device having a wheeled carriage structure with an upwardly telescoping jack and front link having sleeves or couplings for receiving a shovel handle so that it may be rotated axially within a certain range. The jack acts as a fulcrum for lifting snow piled in the scoop by pressing downwardly on the other end of the shovel handle. The handle is then turned axially to dump the snow, which dumping height may be adjusted by changing the length of the telescoping jack.
U.S. Pat. No. 4,130,953 issued to A. T. Bruno on Dec. 26, 1978, entitled “Snow Jack,” discloses another scoop or shovel pivotably mounted to a lever arm mounted on a pedestal connected to a sled or base. The scoop is pivotable in either a horizontal or vertical plane on the pedestal, while a release catch extending along the lever arm to the handle is used to release the scoop and dump the snow. After snow accumulates in the scoop the handle portion of the lever arm is pushed downwardly so that the scoop is lifted off the ground. The release is then actuated, causing the scoop to pivot downwardly on a hinge and release snow in the scoop.
U.S. Pat. No. 5,074,064 issued to J. G. Nickels on Dec. 24, 1991, entitled “Snow Shovel,” discloses a shovel wherein a snow ejection plate forms the bottom wall of the shovel which when swung from a prone to an upright position by pulling upwardly on a hand grip forces snow out of or off of the shovel blade.
In U.S. Pat. No. 5,669,651 issued to A. Vroegindewey on Sep. 23, 1997, entitled “Shovel With Lift Aid Attachment,” a cambered foot pedal attachment is pivotably connected extending rearwardly from the lower end of the handle shaft which when stepped on by the user urges the shovel blade to be raised upwardly by lever action. Also, an auxiliary handle on the forward end of the lever is used to help throw snow off of the shovel blade. At some point, however, the full weight of snow still must be supported by the user.
In U.S. Pat. No. 5,732,933 issued to F. K. Champi on Mar. 31, 1998, entitled “Lifting Implement,” another cambered foot actuated lifting aid attachment for a conventional snow shovel is disclosed. Champi is conceptually similar to the Vroegindewey lifting aid, although it does not include an auxiliary handle, with the lifting aid pivotably connected to the shovel handle by a hinge clamp having a spring therein. A hook is also provided to hold the attachment close to the shovel handle when not in use.
U.S. Pat. No. 6,086,049 issued to D. A. Sheils on Jul. 11, 2000, entitled “Mechanical Assistance Mechanism for Shovels,” discloses another lever-type ground engaging rod connected to a shovel shaft near the shovel blade. The Sheils shovel is also pivotable to the side while being supported on the rod to facilitate dumping of the load.
U.S. Pat. No. 6,203,081 issued to E. B. Kegan, Sr. on Mar. 20, 2001, entitled “Easy Lift Levered Shovel,” discloses another shovel having a lever attachment including a spring arrangement for automatically pivoting the lever legs so that they are adjacent to the shovel handle shaft when there is no load on the shovel handle. Dumping of the snow or load is accomplished by lifting the shovel handle and flinging the snow to the side in the usual manner.
U.S. Pat. No. 6,485,076 issued to W. N. Chang on Nov. 26, 2002, entitled “Versatile Attachment for Shovel,” discloses a pivotable angled rod that may be used both as a handle and a foot engaged lifting lever. The Chang attachment may also slide along the ground to aid in transporting snow to a suitable dumping area. Structurally, such arrangement is different from the present invention, however.
Combination shovels and pusher arrangements or plows are also known in the prior art. For example, U.S. Pat. No. 2,239,297 issued to S. E. Allen et al. on Apr. 22, 1941, entitled “Snow Shovel,” discloses a device that may be used either as a shovel or plow-type device by adjusting the angle of the handle in relation to the shovel blade. A wing-nut is used to secure the blade and handle at the desired angle.
U.S. Pat. No. 4,531,713 issued to F. H. Balboni on Jul. 30, 1985, entitled “Snow Removal Implement,” discloses an implement having a wide rectangular blade, a U-shaped handle, and a pivot or fulcrum member, designed to be pushed across a snow-filled area, with the blade being pivotable upwardly by applying a downward force on the handle, causing snow to be flipped or tossed off the blade. No means for pivoting or releasing the blade after it has been moved to a raised position is shown, nor is a foot lever used to aid in raising the blade off the ground.
U.S. DES. PAT. 275,928 issued to D. R. LoPresti on Oct. 16, 1984, entitled “Levered Shovel Unit,” discloses an ornamental design for another shovel having a lever or fulcrum arrangement similar to those described above.
Push-type wheeled snow shovels or scoops are also commonly found in the prior art. U.S. Pat. No. 3,043,033 issued to H. O. Ingram et al. on Jul. 10, 1962, entitled “Utility Scoop,” discloses an adjustable wheeled manual scoop device having a releasable scoop adjusting assembly having a toothed rack portion and a releasable spring locking arrangement that is actuated by a lever situated near the handle of the scoop. When the lever is pressed a detent is released from the toothed rack, and the angle of the scoop in relation to the handle and wheel assembly can be adjusted to facilitate scooping, carrying and dumping of debris.
U.S. Pat. No. 3,121,963 issued to C. W. Nolan on Feb. 25, 1964, entitled “Shoveling Device,” discloses another wheeled shovel having an independently pivotable subframe including a snow scoop. After the scoop is loaded with snow, it is pivoted upwardly to a horizontal position and is held by a latch member. A chain connected to the rear wall section of the scoop is then pulled, causing such wall section to retract and allowing the load of snow to essentially drop out of the scoop at a dumping location. A counterweight is provided to minimize the physical exertion in pivoting the loaded scoop. The angle of the handle in relation to the scoop makes it impractical or difficult to advance the Nolan device forward along an elongated surface such as the width of a driveway or the like.
U.S. Pat. No. 3,923,331 issued to A. A. Hollnagel on Dec. 2, 1975, entitled “Snow Scoop,” discloses a bucket-type snow scoop designed to be pushed across the ground on a convex ground engaging surface on the bottom side of the scoop as well as runners on a curved frame structure. The scoop is pivotally connected to the frame via a pair of mounting arms. After it is loaded with snow, the bucket is pivoted upwardly by pressing downwardly on the frame handles. A latch may then be released to allow the bucket to pivot forwardly to a dumping position.
U.S. Pat. No. 4,125,951 issued to A. W. Huerth on Nov. 21, 1978, entitled “Snow Removal Device,” discloses another snow scoop or pusher wherein a main body member is connected to a shovel blade portion having raised side walls, plus a handle means. Snow is piled up in the device by pushing it forwardly along the ground with the handle, while the snow is removed from the blade by rapidly decelerating the blade so that the snow is thrown forward. The Huerth device is thus an example of a device designed especially for using accumulated momentum along a surface to propel snow to a specific resting location on such surface.
U.S. Pat. No. 5,018,282 issued to K. Y. Hong on May 28, 1991, entitled “Mechanical Shovel,” discloses a wheeled shovel or snow scoop also having a lever mechanism for emptying the scoop. When downward foot pressure is applied to a bight connected to the lever arm, the scoop slants rearwardly on a pair of gudgeon pins secured in slots on the chassis, and snow is moved to the rear of the scoop. Snow is dumped from the scoop when further pressure is applied to the lever, so that the scoop is angled upwardly and forwardly.
U.S. Pat. No. 5,271,169 issued to K. J. Konsztowicz on Dec. 21, 1993, entitled “Snow Shovel/Pusher,” discloses a combination/convertible snow shovel and plow having a snow pushing blade having a curled-under end so that the blade does not dig into the surface being cleared, which may be a rough or loose stone surface. A handle assembly for pushing the blade on a pair of ski-like runners is provided. No means for lifting or more easily dumping snow from the blade is shown.
U.S. Pat. No. 5,511,327 issued to M. G. Jurkowski et al. on Apr. 30, 1996, entitled “Wheeled Snow Shovelling Device,” discloses a cart-like structure for holding a snow shovel or plow having a large centrally located wheel. The cart may be used as a pivot device to lift the shovel blade, and the cart may be tilted on the large wheel to the side to dump snow on an area adjacent to the area to be cleaned. However, Jurkowski indicates that such shoveling device is effective only in rather light snow accumulations of up to approximately 3 inches.
U.S. Pat. No. 5,918,921 issued to V. Samuelson on Jul. 6, 1999, entitled “Levered Shovel for Moving Snow,” discloses a shovel having a wheel assembly connected to approximately the center of the handle shaft of a shovel, which wheel acts as a fulcrum for the shovel.
U.S. Pat. No. 5,984,393 issued to R. H. Washington on Nov. 16, 1999, entitled “Shovel With Pivoting Head,” discloses a shovel and handle assembly wherein the shovel and handle shaft are joined together by a pivot joint so that the shovel head can rotate around a longitudinal axis with respect to the handle shaft in either a clockwise or counterclockwise direction. Such shovel design reduces the stress caused by the act of turning or twisting and dumping the contents of the shovel, rather than bending and lifting the load. No aid for lifting the load is provided, however, so that a significant amount of bending and lifting is still required.
U.S. Pat. No. 6,053,548 issued to L. G. Bowles, Jr. on Apr. 25, 2000, entitled “Manually-Operable Combination Shovel and Plow for Snow and Other Material,” discloses a shovel wherein the shovel blade is positionable at various fixed angles with respect to the handle. A male and female joint member securable together by pins connects the shovel blade and handle so that the blade may be placed at an angle which is convenient for plowing, rather than shoveling. A toothed and notched opening is provided in the male joint member which allows the blade to be secured at one of three angles or positions with respect to the handle, where it is held by a spring arrangement. When the handle is pulled back or rearwardly, the pins disengage so that the angle of the shovel blade can be adjusted. An auxiliary handle bar is also provided on the main handle to facilitate plowing, and in addition a wheel assembly may be added to the shovel to make plowing even easier.
U.S. Pat. No. 6,457,757 issued to J. D. Hendrick on Oct. 1, 2002, entitled “Snow Shoveling Apparatus With Handle and Blade Adjustable During Movement of Apparatus,” discloses a wheeled shovel wherein the angle of the handle and the blade are adjustable on notched mounting plates. Handle angle and blade angle adjustment levers are also provided so that the settings can be changed during use of the shovel. No additional means for lifting or dumping the snow are disclosed.
While there are obviously, therefore, a large number of shovels having a variety of lifting or dumping aids connectable thereto, each of which is useful for its own purposes, the present inventor's shoveling tool according to this invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus wherein strain and exertion from both lifting and dumping a heavy load of snow is essentially eliminated. Therefore, since none of the prior art arrangements provides a snow lifting and dumping arrangement in accordance with the teachings of the present inventor's device, it can be appreciated that there exists a need for such a device which is both significantly less expensive than a snow blower, but also is more easily used and safer to use from a physiological standpoint than a conventional snow shovel. In this regard, therefore, the present invention substantially fulfills a significant existing need.